© 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Handbook of Smoke Control Engineering © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

ABOUT THE AUTHORS

John H. Klote Dr. John Klote is known throughout the world as an expert in smoke control due to his many books on the topic and his 19 years of fire research conducted at the U.S. National Institute of Standards and Tech- nology (NIST) in Gaithersburg, Maryland. For 11 years, he operated his own consulting company spe- cializing in analysis of smoke control systems. Klote developed a series of smoke control seminars that he teaches for the Society of Fire Protection Engineers. The primary author of the 2007 ICC book A Guide to Smoke Control in the 2006 IBC and the 2002 ASHRAE book Principles of Smoke Management, Dr. Klote is also the primary author of two other ASHRAE books about smoke control, and he has written chapters about smoke control in a number of books, as well as over 80 papers and articles on smoke control, smoke movement, CFD fire simulations, and other aspects of fire protection. He is a licensed professional engi- neer in Washington, DC. Klote earned his doctorate in mechanical engineering from George Washington University. Klote is a member of NFPA, a fellow of SFPE and a fellow of ASHRAE. He is a member and past chair of ASHRAE Technical Committee 5.6, Fire and Smoke Control, and a member of the NFPA Smoke Management Committee.

James A. Milke Professor Milke is the chairman of the Department of Fire Protection Engineering at the University of Maryland. He earned his doctorate in aerospace engineering from the University of Maryland. Milke is an author of the ASHRAE book Principles of Smoke Management, and of the chapters “Smoke Movement in Buildings” and “Fundamentals of Fire Detection” in the 2008 NFPA Fire Protection Handbook.Heis also an author of the chapters “Analytical Methods for Determining Fire Resistance of Steel Members,” “Smoke Management in Covered Malls and Atria,” and “Conduction of Heat in Solids” in the 2008 SFPE Handbook. Milke is a licensed professional engineer in Delaware, a member of NFPA and American Society of Civil Engineers (ASCE), a fellow of SFPE, and a past chairman of the NFPA Smoke Manage- ment Committee.

Paul G. Turnbull Paul Turnbull has been actively involved in the development of codes and standards for smoke control systems for over 24 years. He began his career as a hardware developer, designing RFI power line filters, and later moved into development of control products and accessories for building control systems. He then spent 10 years responsible for safety certifications of building controls, HVAC, fire alarm, and smoke control equipment. For the past 15 years, he has specialized in the development and application of gateways that enable fire alarm, security, and lighting control systems to be integrated with building con- trols in order to provide coordinated operations between these systems. He is an active member in several professional associations focused on control of fire and smoke. Turnbull has a baccalaureate degree in electrical engineering and a master's degree in computer science. He is a member of ASHRAE Technical Committee 5.6, Fire and Smoke Control, and the NFPA Smoke Management Committee. He is an instructor for the SFPE smoke control seminars.

Ahmed Kashef Dr. Kashef is a group leader of Fire Resistance and Risk Management in the Fire Research Program at the Institute for Research in Construction, National Research Council of Canada. He holds a PhD in civil engineering and has more than 20 years research and practical experience. Dr. Kashef’s expertise involves applying numerical and experimental techniques in a wide range of engineering applications including fire risk analysis, fire dynamics, tenability, heat transfer, and smoke transport in the built envi- ronment and transportation systems. He has authored and co-authored more than 180 publications. He has managed a broad range of projects involving modeling and full-scale fire experiments to address fire related issues. This includes projects that investigated the ventilation strategies and detection systems in road and subway tunnels. He is the technical secretary of the ASHRAE Technical Committee 5.6, Fire © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

and Smoke Control, and the chair of the research subprogram of ASHRAE Technical Committee 5.9, Enclosed Vehicular Facilities. Dr. Kashef is a registered professional engineer in the province of Ontario, and a member of the NFPA Technical Committee 502 on Road Tunnel and Highway Fire Protection. He is an associate member of the World Road Association (PIARC), Working Group 4, Ventilation and Fire Control and a corresponding member of the Technical Committee 4 Road Tunnel Operations.

Michael J. Ferreira Michael Ferreira is a senior fire protection engineer and project manager at Hughes Associates, a fire science and engineering consulting company. He has been primarily involved with smoke management system design projects for the past 17 years and has published several articles on the innovative use of computer models for these systems. Ferreira has extensive experience in performing smoke control com- missioning testing and calibrating computer models using field data. He was the lead investigator responsi- ble for evaluating smoke control system performance in NIST’s investigation of the World Trade Center disaster. He has also conducted a performance-based analysis of the smoke control system at the Statue of Liberty. Ferreira is a professional engineer and holds a BS in Mechanical Engineering and an MS in Fire Protection Engineering from Worcester Polytechnic Institute. He is a member of the NFPA Smoke Man- agement Systems Committee, and is an instructor for the NFPA and SFPE smoke control seminars. © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

ASHRAE ASHRAE, founded in 1894, is a building technology society with more than 50,000 members worldwide. The Society and its members focus on building systems, energy efficiency, indoor air quality and sustainability within the industry. Through research, standards writing, publishing, and continuing education, ASHRAE shapes tomorrow’s built environment today. 1791 Tullie Circle, NE Atlanta, GA 30329 1-800-527-4723 www.ashrae.org

International Code Council International Code Council is a member-focused association dedicated to helping the building safety community and construction industry provide safe, sustainable, and affordable construction through the development of codes and standards used in the design, build, and compliance process. Most U.S. communities and many global markets choose the International Codes. ICC Evaluation Service (ICC-ES), a subsidiary of the International Code Council, has been the industry leader in performing technical evalua- tions for code compliance fostering safe and sustainable design and construction. Headquarters: 500 New Jersey Avenue, NW, 6th Floor, Washington, DC 20001-2070 District Offices: Birmingham, AL; Chicago. IL; Los Angeles, CA 1-888-422-7233 www.iccsafe.org

Society of Fire Protection Engineers Organized in 1950, the Society of Fire Protection Engineers (SFPE) is the profes- sional organization that represents engineers engaged in fire protection worldwide. Through its membership of over 5000 professionals and 65 international chapters, SFPE advances the science and practice of fire protection engineering while maintain- ing a high ethical standard. SFPE and its members serve to make the world a safer place by reducing the burden of unwanted fire through the application of science and technology. To become a member, go to www.sfpe.org. 7315 Wisconsin Ave., #620E Bethesda, MD 20814 1-301-718-2910 www.sfpe.org

National Fire Protection Association The National Fire Protection Association (NFPA) is an international nonprofit organization that was established in 1896. The company's mission is to reduce the worldwide burden of fire and other hazards on the quality of life by providing and advocating consensus codes and standards, research, training, and education. 1 Batterymarch Park Quincy, MA 02169-7471 1-617-770-3000 www.nfpa.org © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Handbook of Smoke Control Engineering

John H. Klote James A. Milke Paul G. Turnbull Ahmed Kashef Michael J. Ferreira © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

ISBN 978-1-936504-24-4

2012 John H. Klote. Published by ASHRAE. All rights reserved.

Published in cooperation with International Code Council, Inc., National Fire Protection Association, and Society of Fire Protection Engineers.

ASHRAE 1791 Tullie Circle, N.E. Atlanta, GA 30329 www.ashrae.org

Printed in the United States of America

Printed on 30% post-consumer waste using soy-based inks.

Illustrations by John H. Klote, unless otherwise credited.

ASHRAE has compiled this publication with care, but ASHRAE and its publishing partners have not investigated, and ASHRAE and its publishing partners expressly disclaim any duty to investigate, any product, service, process, procedure, design, or the like that may be described herein. The appearance of any technical data or editorial material in this publication does not constitute endorsement, warranty, or guaranty by ASHRAE and its publishing partners of any product, service, process, procedure, design, or the like. ASHRAE and its publishing partners do not warrant that the information in the publication is free of errors, and ASHRAE and its publishing partners do not necessarily agree with any statement or opinion in this publication. The entire risk of the use of any information in this publication is assumed by the user. No part of this book may be reproduced without permission in writing from ASHRAE, except by a reviewer who may quote brief passages or repro- duce illustrations in a review with appropriate credit; nor may any part of this book be reproduced, stored in a retrieval system, or transmitted in any way or by any means—electronic, photocopying, recording, or other—without permission in writing from ASHRAE. Requests for permission should be submitted at www.ashrae.org/permissions.

Library of Congress Cataloging-in-Publication Data

Handbook of smoke control engineering / John H. Klote, editor and chief ; James A. Milke, Paul G. Turnbull. p. cm. Includes bibliographical references and index. ISBN 978-1-936504-24-4 (hardcover : alk. paper) 1. Buildings--Smoke control systems--Handbooks, manuals, etc. 2. Smoke prevention--Hand- books, manuals, etc. 3. Ventilation--Handbooks, manuals, etc. 4. Fire testing--Handbooks, manuals, etc. I. Klote, John H. II. Milke, J. A. (James A.) III. Turnbull, Paul G., 1961- IV. American Society of Heating, Refrigerating and Air-Conditioning Engineers. TH1088.5.H36 2012 693.8--dc23 2012009054

ASHRAE STAFF PUBLISHING SERVICES SPECIAL PUBLICATIONS David Soltis Mark S. Owen Group Manager of Publishing Services Editor/Group Manager and Electronic Communications of Handbook and Special Publications Jayne Jackson Cindy Sheffield Michaels Publication Traffic Administrator Managing Editor PUBLISHER James Madison Walker W. Stephen Comstock Associate Editor Elisabeth Warrick Assistant Editor Meaghan O’Neil Editorial Assistant Michshell Phillips Editorial Coordinator

Any updates/errata to this publication will be posted on the ASHRAE Web site at www.ashrae.org/publicationupdates. © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

DEDICATION This book is dedicated to the memory of Harold (Bud) Nelson. Because of his many significant contributions when he worked at the General Services Administration (GSA) and the National Institute of Standards and Technology (NIST), Bud Nelson was recognized as one of the great pioneers of fire protection engineering. Bud Nelson also was the first chairman of the NFPA Smoke Management Committee.

vii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

HOW TO USE THIS BOOK

This book is organized in the classic handbook format to help engineers and other professionals who need to get information about a topic quickly. The Table of Contents and the Index can be used so readers can go directly to their topic of interest. The handbook format has no introductory chapter, and the most fundamental material is in the first chapters and applied material is in later chapters. To help readers get information quickly, the chapters do not include derivations of equations. Unlike textbooks, some redundancy is needed in handbooks so that the chap- ters can be relatively independent. This redundancy is minimized, and in some places readers are referred to another section or chapter for more information. This book includes all the information in my earlier smoke con- trol books plus a number of other topics, and there are many example calculations. This handbook can be used as a textbook with the teacher selecting the chapters and parts of chapters to be taught. The only departure from the handbook format is that derivations of equations are in an appendix included to make the book more useful to scholars, teachers, and students.

John H. Klote

viii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

TABLE OF CONTENTS

Dedication vii How to Use This Book viii Preface xxi Acknowledgments xxii Note on Sustainability xxiii

CHAPTER 1—UNITS AND PROPERTIES 1 Dual Units 1 The SI System 1 Chapters in SI Only 2 Temperature Conversion 3 Temperature Difference 3 Soft and Hard Conversions 3 Unit Conversions for Equations 3 Physical Data 8 U.S. Standard Atmosphere 8 Nomenclature 12 References 12

CHAPTER 2—CLIMATIC DESIGN DATA 13 Climatic Data 13 Standard Barometric Pressure 14 Winter Design Temperature 14 Summer Design Temperature 14 Design Wind 14 References 105

CHAPTER 3—FLOW OF AIR AND SMOKE 107 Flow Equations 107 Orifice Flow Equation 107 Density of Gases 108 Exponential Flow 108 Gap Method 109 Bidirectional Flow 112 Pressure Difference 112 Continuous Opening 113 Two Openings 113 Pressure Losses in Shafts 114 Ducts and Shafts 114 Stairwell Flow 116 Flow Areas & Coefficients 116

ix © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Effective Areas 122 Symmetry 124 Driving Forces 125 Buoyancy of Combustion Gases 125 Expansion of Combustion Gases 125 Fan-Powered Ventilation Systems 126 Elevator Piston Effect 126 Stack Effect 128 Wind 131 Nomenclature 134 References 135

CHAPTER 4—TIMED EGRESS ANALYSIS 137 Timeline 137 Analysis Approaches 138 Algebraic Equation-Based Methods 138 Velocity 139 Density 139 Specific Flow 140 Flow 141 Simplified Method 142 Individual Component Analysis 142 Computer-Based Evacuation Models 143 Egress system 145 Human Behavior Modeling 145 Individual tracking 145 Uncertainty Reference 145 Summary 145 Human Behavior 146 Premovement 146 Nomenclature 146 References 147

CHAPTER 5—FIRE SCIENCE AND DESIGN FIRES 149 Design Fires 149 Avoid Wishful Thinking 149 Transient Fuels 149 Decision Tree 150 HRR per Unit Area 150 Stages of Fire Development 151 Fire Growth 151 Flashover 153 Fully Developed Fire 154 Fire Decay 154 Sprinklers 154 HRR decay 155 Sprinkler Actuation 155 Shielded Fires 156 Measurement of HRR 158

x © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Oxygen Consumption Calorimetry 158 HRR of Objects 159 Radiant Ignition 165 Fuel Packages 166 Nomenclature 168 References 169

CHAPTER 6—HUMAN EXPOSURE TO SMOKE 171 Time Exposure 171 Exposure to Toxic Gases 171 CO and CO2 171 Gas Exposure Models 172 Animal Tests & the FED Model 172 N-Gas Model 173 Exposure to Heat 174 Exposure to Thermal Radiation 176 Smoke Obscuration 177 Reduced Visibility 178 Calculating Reduced Visibility 179 Nonuniform Smoke 181 Tenability 184 Exposure Approaches 185 Heat Exposure 186 Thermal Radiation Exposure 186 Reduced Visibility 186 Toxic Gases Exposure 186 Nomenclature 188 References 188

CHAPTER 7—AIR-MOVING SYSTEMS AND EQUIPMENT 191 Residential Systems 191 Perimeter and Core Zones 191 Individual Room Units 192 Forced-Air Systems 192 Types of Systems 193 Other Special-Purpose Systems 195 Fans 196 Centrifugal Fans 196 Axial Fans 197 Dampers 198 Fire Dampers 198 Smoke Dampers 199 Combination Fire/Smoke Dampers 200 References 200

CHAPTER 8—CONTROLS 201 Control Systems 201 Listings 201 Activation of Smoke Control 202 Automatic 202

xi © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Manual 203 Firefighter’s Smoke Control Station (FSCS) 203 Control Priorities 204 Control of System Outputs 205 Activation Schedules 205 Response Times 206 Interface to Other Building Systems 207 Hardwired 207 Gateway 208 Shared Network Wiring 208 Example Control Circuit Diagrams 209 Nondedicated Fan with Shared ON/OFF Control 209 Nondedicated Fan with Separate ON/OFF Controls for Smoke Control and Normal Operation 210 Dedicated Stairwell Pressurization Fan 210 Dedicated Smoke Damper 211 System Reliability 211 Normal Operation as a Method of Verification 211 Electrical Supervision 212 End-to-End Verification 212 Automatic Testing 213 Manual Testing 213 Sensing Devices 213 Best Practices 214 Use of a Single Control System to Coordinate Smoke Control 214 Control of Devices that are Not Part of the Smoke Control System 216 References 216

CHAPTER 9—BASICS OF PASSIVE AND PRESSURIZATION SYSTEMS 217 Passive Smoke Control 217 Pressurization Concept 218 Opening and Closing Doors 218 Validation Experiments 218 Henry Grady Hotel Tests 218 30 Church Street Tests 219 Plaza Hotel Tests 220 The NRCC Experimental Fire Tower 220 Smoke Feedback 221 Wind 221 Design Pressure Differences 221 Minimum Pressure Difference 222 Maximum Pressure Difference 223 Analysis Approach for Pressurization Systems 224 Nomenclature 225 References 225

CHAPTER 10—PRESSURIZED STAIRWELLS 227 Design and Analysis 227 Simple Systems in Simple Buildings 227 Systems in Complicated Buildings 228

xii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Pressurization Systems 228 Single and Multiple Injection 229 Compartmentation 230 Vestibules 230 System with Fire Floor Exhaust 230 Stairwell Temperature 231 Untreated Pressurization Air 231 Analysis by Algebraic Equations 231 Pressure Differences 232 Average Pressure Differences 234 Stairwell Supply Air 234 Height Limit 237 Example Calculations 238 Rule of Thumb 238 Systems with Open Doors 239 Doors Propped Open 239 Need for Compensated Systems 239 Compensated and the Wind 242 Compensated Systems 242 Nomenclature 245 References 245

CHAPTER 11—PRESSURIZED ELEVATORS 247 Design and Analysis 247 Design Pressure Differences 248 Shaft Temperature 548 Elevator Top Vent 248 Piston Effect 249 Volumetric Flow 249 Pressurization Systems 249 Basic System 249 Exterior Vent (EV) System 254 Floor Exhaust (FE) System 256 Ground Floor Lobby (GFL) System 259 References 264

CHAPTER 12—ELEVATOR EVACUATION SYSTEMS 265 Elevator Evacuation Concept 265 Availability 265 Elevator Control 266 Human Considerations 266 EEES Protection 267 Heat and Flame 267 Smoke 267 Water 267 Overheating of Elevator Room Equipment 267 Electrical Power 267 Earthquakes 267 Fire Inside the EEES 268

xiii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Elevator Smoke Control 268 Design Pressure Differences 268 Analysis 268 Piston Effect 268 Top Vent 268 Pressurization Systems 268 Elevator Evacuation Time 269 Evacuation Time 269 Start-Up Time 270 Elevator Round Trip Time 270 Standing Time 271 Travel Time 274 Nomenclature 276 References 277

CHAPTER 13—ZONED SMOKE CONTROL 279 Zoned Smoke Control Concept 279 Smoke Zone Size and Arrangement 279 Interaction with Pressurized Stairs 281 Analysis 282 Use of HVAC System 282 Separate HVAC Systems for Each Floor 282 HVAC System for Many Floors 284 Dedicated Equipment 285 Zoned Smoke Control by Pressurization and Exhaust 285 Zoned Smoke Control by Exhaust Only 286 Exhaust Fan Temperature 286 Exterior Wall Vents 287 Smoke Shafts 288 Nomenclature 289 References 289

CHAPTER 14—NETWORK MODELING AND CONTAM 291 Purpose of Network Modeling 291 Early Network Models 291 Network Model 293 Mass Flow Equations 293 Contaminant Flow 294 CONTAM Features 294 Zone Pressures 294 Wind 294 CONTAM Output 295 CONTAM User Information 295 CONTAM Representation of a Floor 296 CONTAM Window 297 Pop-Up Menu 299 Speeding up Data Input 301 Check for Missing Items 301 Paste Groups of Levels Quickly 301

xiv © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Use the Multiplier with Leakages 301 Use Dummy Wind Data 301 Use Temperature Schedule 301 CONTAM Examples 302 Nomenclature 313 References 313

CHAPTER 15—BASICS OF ATRIUM SMOKE CONTROL 315 Design Scenarios 315 Design Approaches 316 Natural Smoke Filling 317 Steady Mechanical Smoke Exhaust 317 Unsteady Mechanical Smoke Exhaust 317 Steady Natural Venting 317 Unsteady Natural Venting 317 Methods of Analysis 317 Algebraic Equations 317 Zone Fire Modeling 318 CFD Modeling 318 Scale Modeling 318 Atrium Temperature 319 Minimum Smoke Layer Depth 319 Makeup Air 319 Wind 320 Plugholing 320 Control and Operation 321 Stratification 321 Smoke Filling Equations 321 Steady Filling 323 Unsteady Filling 324 Irregular Geometry 324 Slightly Irregular Ceilings 324 Sensitivity Analysis 325 Natural Venting Equation 325 Airflow Equations 327 Time Lag 329 Steady Fires 329 T-Squared Fires 330 Smoke Layer with Sprinkler Action 331 Nomenclature 331 References 331

CHAPTER 16—EQUATIONS FOR STEADY ATRIUM SMOKE EXHAUST 333 Smoke Production 333 Axisymmetric Plume 333 Simplified Axisymmetric Plume 336 Plume Diameter 337 Wall and Corner Plumes 337 Balcony Spill Plume 338 Window Plume 340

xv © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Average Plume Temperature 341 Smoke Layer Temperature 341 Plugholing 342 Volumetric Flow Rate 343 Density of Smoke 343 Case Study 343 Nomenclature 348 References 349

CHAPTER 17—FIRE AND SMOKE CONTROL IN TRANSPORT TUNNELS 351 Fire Safety Issues in Tunnels 351 Fire Protection Matrix 352 Fire Development in Tunnels 352 Backlayering 354 Smoke Layer Speed and Depth 354 Methods of Smoke Management 354 Visibility 355 Exits and Other Safety Facilities 356 Road Tunnels 356 Rail and Subway Tunnels 356 Smoke Management Systems in Tunnels 356 Natural Ventilation Systems 356 Mechanical Ventilation Systems 357 On-Site Evaluation of Ventilation Systems Performance 364 Design Fire 365 Design Fire Scenarios 366 Numerical Modeling 367 One-Dimensional models (1D) 367 Zone Models (2D Models) 367 Computational Fluid Dynamics (CFD) (3D) 367 Detection 368 Performance Criteria 369 Available Detection Technologies 369 Nomenclature 369 References 370

CHAPTER 18—ZONE FIRE MODELING 373 Zone Model Concept 373 Sprinkler Actuation 374 Model Evaluation 374 Algebraic Equation Approach 374 Plume Flow 376 Differential Equation Approach 376 CFAST 378 Example Input File 379 Menus 380 Fires 380 Examples 384 Nomenclature 385 References 385

xvi © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

CHAPTER 19—TENABILITY ANALYSIS AND CONTAM 387 Near Fire Limitation 387 The Two Field Approach 387 Zone Fire Modeling of the Near Field 388 Adapting Zone Fire Model Results 390 Modeling with CONTAM 390 Two-Way Flow Paths 391 Contaminant Generation and Flow 391 Tenability Calculations 392 Use of CONTAM 394 CONTAM Input 394 Examining Results 397 Tenability Examples 399 Nomenclature 402 References 402

CHAPTER 20—COMPUTATIONAL FLUID DYNAMICS 405 Tenability Analysis 405 CFD Concept 405 Example Applications 406 Boundary Conditions 406 Realism 406 Model Evaluation 407 Governing Equations 407 Turbulence Modeling 408 Fire Modeling 408 Fuel Mixtures 409 Modeling the Space 409 Nonrectangular Geometry 410 Visualization 410 Modeling Technique 411 Atrium Smoke Control 412 Natural Venting 413 Stairwell Ventilation Systems 413 Nomenclature 415 References 416

CHAPTER 21—SCALE MODELING 417 Dimensionless Groups 417 Similitude 419 Froude Modeling 419 Reynolds Number 420 Heat Transfer 421 Construction of Model 421 Instrumentation 421 Example 421 Nomenclature 422 References 423

CHAPTER 22—FULL-SCALE FIRE TESTING 425 Research and Testing 425

xvii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Documentation 426 Project Plan 426 Safety Plan 426 Final Report 426 Test Facility 426 Fire Test Setup 427 Fire Hardening 429 Video 429 Fires and Fuels 429 Instrumentation 430 Instrument Wiring 431 Prefire Check 431 Temperature 432 Heat Flux 435 Pressure Difference 435 Velocity 438 Gas Concentration 438 Smoke Obscuration 440 Load Cells and Load Platforms 440 Nonfire Measurements 440 Pressure Difference 441 Velocity 442 Volumetric Flow 442 Data Reduction and Analysis 443 Data Smoothing 444 Nomenclature 446 References 446

CHAPTER 23—COMMISSIONING AND SPECIAL INSPECTIONS 449 Commissioning Processes 449 Roles and Responsibilities 449 Recommended Documentation 450 Special Inspection Phases 450 Installation and Component Verification 450 Inspection and Equipment Functional Testing 451 Sequence of Operations Testing 454 System Performance Testing 455 Measuring Performance 457 Door-Opening Forces 457 Automatic Sensors 457 Chemical Smoke 457 Zoned Smoke Control 458 Atrium Demonstration Testing 458 Other Uses of Smoke Bombs 460 References 460

CHAPTER 24—PERIODIC TESTING 461 Factors Impacting Testing 461 Architectural Changes 461

xviii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Equipment Maintenance 462 Sensors and Instrumentation 462 Environmental Factors 462 Recommended Testing 463 Manual Testing 463 Automatic Testing 465 Roles and Responsibilities 469 Manual Testing 469 Automatic Testing 469 References 469

Appendix A—Derivations of Equations 471

Index 481

xix © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

PREFACE

In 1983, ASHRAE published Design of Smoke Control Systems for Buildings by John Fothergill and me. This book was the first attempt to consolidate and present practical information about smoke control design. Judging by the many favorable comments and suggestions about this first book, I feel that it was a success. The first publication was limited to systems that control smoke by means of the physical mechanisms of pressurization and airflow. In 1992, ASHRAE and SFPE jointly published Design of Smoke Management Systems by James Milke and me. The term smoke management was used in the title of this publication to indicate that the physical mechanisms were expanded from pressurization and airflow to include compartmentation, dilution, and buoyancy. Based on heightened concerns about supplying combustion air to the fire, a caution was added about the use of airflow for smoke manage- ment. In 2002, ASHRAE and SFPE jointly published Principles of Smoke Management by James Milke and me. This publication included the material of the two earlier books plus people movement in fire, hazard analysis, scale model- ing, and computational fluid dynamics. This new publication is in handbook form that is intended to make the book more useful to practicing engineers. The earlier books were aimed at both practicing engineers and students, and derivations of equations were included in many of the chapters. To make the handbook easier to use for engineers who want information on a specific topic quickly, the derivations are not included in the chapters. However, to make the book useful to students and teachers, the derivations are in an appendix. This new book addresses the material of the earlier books plus (1) controls, (2) fire and smoke control in trans- port tunnels, and (3) full scale fire testing. For those getting started with the computer models CONTAM and CFAST, there are simplified instructions with examples. As with the other books, this new book is primarily intended for designers, but it is expected that it will be of interest to other professionals (architects, code officials, researchers, etc.). In this book, the term smoke control system is used to mean an engineered system that includes all methods that can be used singly or in combination to modify smoke movement. This usage is consistent with that of the 2009 NFPA 92A, 2012 NFPA 92, and most codes including the International Building Code. This usage is a departure from the earlier ASHRAE smoke control books and earlier versions of NFPA 92A. The meaning of the term smoke man- agement system was completely changed in the 2009 NFPA 92A, and this term is almost never used in this handbook. Because these terms have different meanings in many publications, readers are cautioned to be careful about this ter- minology when reading different books, research papers, and articles. This book and its predecessors are different from other design books in a number of respects. This book is writ- ten in both English units (also called I-P for inch-pound) and SI units so that it can be used by a wide audience. Phys- ical descriptions are worked into the text as simple explanations of how particular mechanisms, processes or events happen. Many example calculations are included. As with the earlier book, I hope that this book is of value to the engineering community. Further, I invite readers to mail their suggestions and comments to me at the address below. John H. Klote, D.Sc., P.E. 19355 Cypress Ridge Terrace Unit 502 Leesburg, VA 22101

xxi © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

ACKNOWLEDGMENTS

This project would not have been possible without the support of ASHRAE. In addition to publishing books about smoke control, ASHRAE has funded a considerable body of smoke control research from the 1980s to the present time. A debt is owed to my coauthors: James A. Milke, Paul G. Turnbull, Ahmed Kashef, and Michael J. Ferreira. Each of them has authored a chapter or more, and they have provided valuable advice during development of this handbook. Acknowledgement is made to the members of the ASHRAE Smoke Control Monitoring Committee for their generous support and constructive criticism. The members of this subcommittee are: William A. Webb (Chair), Jeffrey S. Tubbs, and Douglas Evans. Gary D. Lougheed, Paul G. Turnbull, John A. Clark, John Breen, and W. Stuart Dols also provided constructive criticism. Special thanks are due to Gary Lougheed for his insightful comments regarding fluid flow, design fires, and full scale fire testing. Paul Turnbull made valuable comments about practically every aspect of the book. John Clark provided helpful comments in a number of areas. John Breen, who is a student at the Department of Fire Protection Engineering at the University of Maryland, made valuable comments regarding the computer program CONTAM. W. Stuart Dols, who is in charge of the development of CONTAM at NIST, made helpful comments about a number of aspects of CONTAM. In addition to chairing the review subcommittee, Bill Webb made practical comments on subjects in every chapter of the book. Acknowledgement must be made to the many engineers and scientists who have conducted the research that is the foundation of modern smoke control technology. These researchers are too many to mention here, but many of their efforts are referenced in the text. It should be mentioned that I personally owe much to the National Institute of Standards and Technology in Gaithersburg, MD for the opportunity of being able to do fire research there for nineteen years. The content of this book is heavily dependent on extensive smoke control research conducted at the National Research Council of Canada (NRCC). Much of this research has been conducted at NRCC’s Experimental Fire Tower near Ottawa. John H. Klote

xxii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

NOTE ON SUSTAINABILITY

Sustainability has attracted considerable attention in recent years, and the design of green buildings requires ingenuity and understanding of the technology. This handbook does not explicitly address sustainability, but it can be thought of as a treatment of sustainability to the extent that designers can develop sustainable smoke control systems based on information provided herein. In one sense, smoke control systems can be thought of as sustainable systems in that they can minimize the extent of smoke damage to building components during fires. However, the amount of materials used in some smoke control systems can be minimized or even eliminated. The use of natural smoke venting for smoke control in atria and other large volume spaces eliminates the fans and ductwork used in conventional smoke exhaust systems. The only equipment needed for this kind of venting is a roof vent that opens in the event of a fire. Natural smoke venting has been used for many decades in the United Kingdom, Australia, and Japan. An algebraic equation in Chapter 15 can be used as a starting point for analysis of a natural venting system. Wind effects are a special concern with natural smoke venting, and these systems should be analyzed with computational fluid dynamic (CFD) modeling (Chapter 20). Smoke filling is the simplest form of smoke control for atria and other large volume spaces, because it eliminates the need for any equipment. This approach consists of allowing smoke to fill the large volume space without any smoke exhaust or other smoke removal. For very large spaces, the smoke filling time can be long enough for evacua- tion. Smoke filling time can be calculated by algebraic equations or with the use of computer models as discussed in Chapter 15. It is essential that calculations of evacuation time include the times needed for recognition, validation, and premovement as discussed in Chapter 4. For some applications, passive smoke control using smoke barriers has the potential to be used in place of pres- surization smoke control systems. This can reduce or eliminate the fans and ductwork of the pressurization systems. Such systems need to provide equivalent life-safety protection as that of the pressurization systems. The tenability of such passive systems can be analyzed with CFD modeling or with a combination of CONTAM and zone fire model- ing as discussed in Chapter 19. Stairwell ventilation systems have the potential to maintain tenability in stairwells at reduced fan capacity compared to stairwell pressurization. The idea of these ventilation systems is to supply air to and exhaust air from the stairwell so that any smoke leaking into the stairwell is diluted to maintain tenable conditions in the stairwell. The amount of air needed for stairwell pressurization is proportional to the number of floors served by the stair- well, but the amount of air needed for stairwell ventilation, is almost independent of the number of floors. This means that the greatest savings in fan capacity are for stairwells in very tall buildings. For stairwell ventilation the most important location is the landing of the fire floor, and tenability here can be analyzed by CFD modeling as discussed in Chapter 20. The extent to which smoke control systems can be more sustainable depends on the ingenuity, creativity, and knowledge of the design team. Some old ideas (such as smoke shafts and smoke venting with exterior wall vents) may be reevaluated and revised to become sustainable systems or parts of sustainable systems. It is essential that the alter- nate smoke control systems provide protection that is equivalent to that of conventional systems.

xxiii © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission. © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

CHAPTER 1

Units and Properties John H. Klote

The international system (SI) of units is used for system. Each version has its own rules for dealing with almost all applications outside the U.S. and for many units, but these are not discussed here. The approach applications inside the U.S. In the U.S., a collection of taken here is to focus on the SI system, and to provide mostly old English units are used for many applications. conversions between the I-P units and SI units. These old style units are referred to here as inch-pound (I-P) units. This chapter deals with units of measure- THE SI SYSTEM ment and physical properties. Today’s SI system is based on the metric system DUAL UNITS that was first adopted in France in 1791. This section is a general discussion of the SI system. More detailed Most equations in this handbook are presented in information is available from NIST (Thompson and dual units, but exceptions are noted at the beginning of Taylor 2008) and IEEE/ASTM (IEEE/ASTM 2002). some chapters. The equation below for the Reynolds The NIST publication can be downloaded over the Inter- number is an example of these dual units. net at no cost. The SI system consists of base units and derived 1.39 10–3D U units which together form what is called a coherent sys- R = ------h e v tem of SI units. Such a coherent system needs no addi- (1.1) tional factors in equations to adjust for the units, and the DhU Re = ------for SI advantage of this is illustrated later. The seven base v quantities upon which the SI system is founded are where length, mass, time, thermodynamic temperature, electric R = Reynolds number, dimensionless, current, amount of substance, and luminous intensity. e Table 1.1 lists the names and symbols of the units for Dh = hydraulic diameter of flow path, in. (m), these base quantities. U = average velocity in flow path, fpm (m/s), Derived units are expressed algebraically in terms 2 2 ν = kinematic viscosity, ft /s (m /s). of base units or other derived units. The symbols for This equation consists of an I-P version followed by derived units are obtained by means of the mathematical an SI version. The “where” list below the equation con- operations of multiplication and division. For example, tains the variable names, followed by the I-P units with the derived unit for the derived quantity mass flow the SI units in parentheses. For example, the I-P units of (mass divided by time) is the kilogram per second, and average velocity in flow path are fpm, and the SI units for the symbol for mass flow is kg/s. Other examples of this variable are m/s. derived units expressed in terms of SI base units are The I-P units are used in the following systems: (1) given in Table 1.2. the pound-mass and pound-force system, (2) the slug There are a number of coherent derived units that and pound system, and (3) the pound-mass and poundal have special names and symbols. For example, the pascal

1 © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Chapter 1—Units and Properties is the special unit for pressure, and the symbol Pa is the Care needs to be taken because units with a prefix are special symbol for the pascal. Table 1.3 lists some of not coherent except for the kilogram, which is an excep- these units with special names and symbols. When it is tion. For example, the following is an SI equation for the stated that an equation is valid for the SI system, it is pressure difference between two nodes: meant that the equation is valid for variables that are the  p p – p += p gz – z  (1.2) coherent units of the SI system. ij i j i i j Prefixes are listed in Table 1.4. For example, the pre- where fix kilo (k) means a multiplication factor of one thousand, pij = pressure difference from node i to node j, and a kilometer (km) is a thousand meters (m). Conver- pi = pressure at node i, sions between I-P and SI units are listed in Table 1.5. pj = pressure at node j, r = density of gas at node i, Chapters in SI Only i zi = elevation of node i, Some of the chapters in this handbook are only in zj = elevation of node j, SI units. This was done because the equations in these g = acceleration of gravity. chapters are intended primarily for explanation. These It can be seen from Table 1.3 that the pressures and equations can also be used to write computer programs, the pressure difference are in the units of pascals (Pa). and most computer programs are written in SI units Elevations are quantities of length, and they are in because they are based on equations from research done meters (m) as can be seen from Table 1.1. From in SI units. All of the variables in an SI equation are in Table 1.2, it can be seen that the acceleration term has base units or coherent derived units (Tables 1.1 to 1.3). units of meter per second squared (m/s2).

Table 1.1: Base Units of the SI System Table 1.2: Some Coherent Derived Units

Base Quantity Unit Symbol Quantity Name Symbol Length meter m Acceleration meter per second squared m/s2 Mass kilogram kg Area square meter m2 Time second s Density kilogram per cubic meter kg/m3 Thermodynamic temperature1 kelvin K Electric current ampere A Mass flow mass per second kg/s Amount of substance mole mole Velocity meter per second m/s Luminous intensity candela cd Volume cubic meter m3 1 This is also called absolute temperature. Kelvin is also the unit for 3 temperature difference and temperature rise. Volumetric flow cubic meter per second m /s

Table 1.3: Some Coherent Derived Units with Special Names and Symbols Special Special Expression in other Expression in SI Quantity Name Symbol SI Units Base Units Electrical charge coulomb C – s A

Electric potential difference volt V W/A m2 kg s–3 A–1 Energy, heat, and work joule J N m m2 kg s–3 Force newton N – mkgs–2 Frequency hertz Hz – s–1 Power, heat release rate watt W J/s m2 kg s–3 Pressure, pressure difference pascal Pa N/m2 m–1 kg s–2

2 © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Handbook of Smoke Control Engineering

TEMPERATURE CONVERSION hard about a hard conversion is deciding how many digits should be kept in the rounded number. Should 810 ft be The SI unit of absolute temperature is kelvin, and rounded to 250 m, 247 m, or something else? The answer the I-P unit of absolute temperature is Rankine. In addi- depends on numerous considerations, some of which are tion, temperature is frequently measured in the Celsius unique to specific areas of engineering. or the Fahrenheit scale. The following equations can be used to convert between temperature scales: In this handbook, hard conversions are used. Often, values are rounded to three significant digits T F = T R – 459.67 because calculations based on such rounding are T T 459.67+= equivalent for engineering purposes in both systems. R F Rounding is sometimes based on accuracy consider- T C = T K – 273.15 ations of the original value. With most research work T T 273.15+= (1.3) and some standards, the original value is in SI units. K C For consistency in this handbook, I-P units are listed T F 1.8T C 32+= first, followed by SI units in parentheses, regardless of T – 32 the source of the data. T ------F -= C 1.8 UNIT CONVERSIONS FOR EQUATIONS where

TF = temperature in degrees Fahrenheit, Because almost all research is conducted in SI units, there is a need to convert SI equations to I-P equa- TR = temperature in degrees Rankin, tions. This section discusses a method that can be used TC = temperature in degrees Celsius, for such conversions. For SI equations with temperature TK = temperature in kelvin. in degrees Celsius, the equation needs to be converted to one with temperature in kelvin. Temperature Difference The following is an equation in functional form: This section deals with temperature difference, tem- perature rise, and temperature drop. All of these are han- y = fx 1x2  xn (1.5) dled the same way, and they are referred to here in a generic sense as temperature difference. The following where y is a dependent variable, and x from i =1ton are equations can be used for temperature difference conver- i independent variables. Equation 1.5 is in SI units, and it is sions: desired to convert it to I-P units. The variables in this equation are related to the ones in the other unit system as T F = 1.8T C follows: T F = T R (1.4) T F yay=  T C = ------(1.6) 1.8 xi = bixi T C = T K where Table 1.4: SI Prefixes

TF = temperature difference in degrees Fahrenheit, Prefix Symbol Multiplication Factor

TC = temperature difference in degrees Celsius, giga G 109 = 1 000 000 000 TK = temperature difference in kelvin, mega M 106 = 1 000 000 TR = temperature difference in degrees Rankine. kilo k 103 = 1 000 1 c –2 SOFT AND HARD CONVERSIONS centi 10 = 0.01 milli m –3 Many people are confused by the terms soft conver- 10 = 0.001 sion and hard conversion, because the terms seem back- micro μ 10–6 = 0.000 001 wards. Regarding conversions, soft means exact or nearly nano n 10–9 = 0.000 000 001 so, and hard means approximate. An example of a soft conversion is 810 ft equals exactly 246.888 m. What is 1The prefix centi is to be avoided where possible.

3 © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Chapter 1—Units and Properties

Table 1.5: Factors for Unit Conversions TO CONVERT FROM TO MULTIPLY BY Acceleration foot per second squared (ft/s2) meter per second squared (m/s2) 0.3048 meter per second squared (m/s2) foot per second squared (ft/s2) 3.2808 standard gravity (g) meter per second2 (m/s2) 9.80665 standard gravity (g) foot per second (ft/s2) 32.174 Area

foot squared (ft2) meter2 (m2) 0.09290 foot squared (ft2) inch squared (in.2) 144 meter squared (m2) foot squared (ft2) 10.76 meter squared (m2) inch squared (in2) 1550 meter squared (m2) yard squared (yd2) 1.196 yard squared (yd2) meter2 (m2) 0.8361 yard squared (yd2) foot squared (ft2) 9 yard squared (yd2) inch squared (in.2) 1296 Density

gram per cubic meter (g/m3) kilogram per cubic meter (kg/m3) 0.001 kilogram per cubic meter (kg/m3) gram per cubic meter (g/m3) 1000 gram per cubic meter (g/m3) pound per cubic foot (lb/ft3) 6.2428E-5 kilogram per cubic meter (kg/m3) pound per cubic foot (lb/ft3) 0.062428 pound per cubic foot (lb/ft3) kilogram per cubic meter (kg/m3) 16.018 pound per cubic foot (lb/ft3) gram per cubic meter (g/m3) 16,018 Energy (also Heat and Work) British thermal unit (Btu) joule (J) 1055 British thermal unit (Btu) foot pound (ft lb) 778 erg joule (J) 1.000E-7 foot pound (ft lb) joule (J) 1.356 joule (J) British thermal unit (Btu) 9.479E-4 Flow, Mass kilogram per second (kg/s) pound per hour (lb/h) 7937 kilogram per second (kg/s) pound per minute (lb/min) 132.3 kilogram per second (kg/s) pound per second (lb/s) 2.205 kilogram per second (kg/s) standard cubic feet per min (scfm) at 68°F 1760 pound per hour (lb/h) kilogram per second (kg/s) 0.0001260 pound per minute (lb/min) kilogram per second (kg/s) 0.007560 pound per second (lb/s) kilogram per second (kg/s) 0.4536 pound per second (lb/s) standard cubic feet per min (scfm) at 68°F 798.5 standard cubic feet per min (scfm) at 68°F kilogram per second (kg/s) 0.005680 standard cubic feet per min (scfm) at 68°F pound per second (lb/s) 0.0012523

4 © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Handbook of Smoke Control Engineering

Table 1.5: Factors for Unit Conversions (Continued) TO CONVERT FROM TO MULTIPLY BY Flow, Volumetric foot cubed per minute (ft3/min or cfm) meter cubed per second (m3/s) 4.719E-04 foot cubed per second (ft3/s) meter cubed per second (m3/s) 0.02832 gallon per minute (gal/min or gpm) meter cubed per second (m3/s) 6.309E-05 meter cubed per second (m3/s) foot cubed per minute (ft3/min or cfm) 2119 meter cubed per second (m3/s) foot cubed per second (ft3/s) 35.31 meter cubed per second (m3/s) gallon per minute (gal/min or gpm) 15850 gallon per minute (gal/min or gpm) foot cubed per minute (ft3/min or cfm) 0.1337 foot cubed per minute (ft3/min or cfm) gallon per minute (gal/min or gpm) 7.481 Force kilogram-force (at sea level) newton (N) 9.80665 pound-force (lb) newton (N) 4.448 newton (N) pound-force (lb) 0.2248 Heat (See Energy)

Heat Release Density

Btu/s ft2 kW/m2 11.36 kW/m2 Btu/s ft2 0.08806 Heat Release Rate (see Power) Length foot (ft) meter (m) 0.3048 foot (ft) inch (in.) 12 inch (in.) meter (m) 0.02540 inch (in.) centimeter (cm) 2.54 inch (in.) foot (ft) 0.08333 meter (m) foot (ft) 3.2808 meter (m) inch (in) 39.3701 meter (m) nautical mile (U.S.) 0.0005 meter (m) mile 6.214E-4 meter (m) yard 1.0936 mile meter (m) 1609.3 mile foot (ft) 5280 nautical mile (U.S.) meter (m) 1852 yard meter (m) 0.9144 yard foot (ft) 3 yard meter (m) 0.9144 Light footcandle lux (lx) 10.764 lux (lx) footcandle 0.0929 Mass gram (g) kilogram (kg) 0.001

5 © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Chapter 1—Units and Properties

Table 1.5: Factors for Unit Conversions (Continued) TO CONVERT FROM TO MULTIPLY BY gram (g) pound (lb) 0.002205 kilogram (kg) gram (g) 1000 kilogram (kg) pound (lb) 2.205 ounce (avoirdupois) kilogram (kg) 0.03110 pound (lb) kilogram (kg) 0.4536 pound (lb) gram (g) 453.6 pound (lb) slug 0.03108 slug kilogram (kg) 14.60 slug pound (lb) 32.174 ton (long, 2240 lb) kilogram (kg) 1016 ton (metric) kilogram (kg) 1000 ton (short, 2000 lb) kilogram (kg) 907.2 Mass Flow (see Flow, Mass) Temperature (see equations in the text) Power (also Heat Release Rate) British thermal unit per hour (Btu/h) kilowatt (kW) 2.931E-04 British thermal unit per hour (Btu/h) watt (W) 0.293 British thermal unit per minute (Btu/min) watt (W) 17.58 British thermal unit per minute (Btu/min) kilowatt (kW) 0.01758 British thermal unit per second (Btu/s) watt (W) 1055 British thermal unit per second (Btu/s) kilowatt (kW) 1.055 horsepower watt (W) 745.7 horsepower foot pound per second (ft lb/s) 550.0 horsepower kilowatt (kW) 0.7457 ton (refrigeration) watt (W) 3517 ton (refrigeration) kilowatt (kW) 3.517 Pressure atmosphere, standard (atm) pascal (Pa) 101325 atmosphere, standard (atm) pound per square inch (lb/in.2 or psi) 14.696 atmosphere, standard (atm) pound per square foot (lb/ft2) 2116.2

atmosphere, standard (atm) inch of water (in. H20) at 60 °F 407.19

atmosphere, standard (atm) foot of water (ft H20) at 60 °F 33.932 centimeter of mercury (cm Hg) at 0°C pascal (Pa) 1333.22

centimeter of water (cm H2O) 60°C pascal (Pa) 97.97

foot of water (ft H20) at 60°F pascal (Pa) 2986 inch of mercury (in. Hg) pascal (Pa) 3386

inch of water (in. H20) at 60°F pascal (Pa) 248.84 pascal (Pa) inch of mercury (in. Hg) 2.953E-04

pascal (Pa) inch of water (in. H20) at 60°F 0.004019

pascal (Pa) foot of water (ft H20) at 60°F 3.349E-04 pascal (Pa) centimeter of mercury (cm Hg) at 0°C 7.501E-04

6 © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Handbook of Smoke Control Engineering

Table 1.5: Factors for Unit Conversions (Continued) TO CONVERT FROM TO MULTIPLY BY pascal (Pa) centimeter of water (cm H2O) 60° C 0.01021 pascal (Pa) pound per square foot (lbf/ft2) 0.02089 pascal (Pa) pound per square inch (lbf/in2 or psi) 1.450E-04 pound per square foot (lbf/ft2) pascal (Pa) 47.88 pound per square inch (lbf/in.2 or psi) pascal (Pa) 6895 Velocity (also Speed) foot per hour (ft/h) meter per second (m/s) 8.467E-05 foot per minute (ft/min or fpm) meter per second (m/s) 0.005080 foot per second (ft/s) meter per second (m/s) 0.3048 kilometer per hour (km/h) meter per second (m/s) 0.2778 knot meter per second (m/s) 0.5144 meter per second (m/s) foot per minute (ft/min or fpm) 196.9 meter per second (m/s) foot per second (ft/s) 3.281 meter per second (m/s) foot per hour (ft/h) 11811 meter per second (m/s) kilometer per hour (km/h) 3.600 meter per second (m/s) knot 1.944 meter per second (m/s) mile per hour (mi/h or mph) 2.237 mile per hour (mi/h or mph) kilometer per hour (km/h) 1.609 Volume foot cubed (ft3) meter cubed (m3) 0.02832 foot cubed (ft3) inch cubed (in.3) 1728 foot cubed (ft3) gallon (U.S.) 7.4805428 foot cubed (ft3) yard cubed (yd3) 0.03704 gallon (U.S.) meter cubed (m3) 0.003785412 gallon (U.S.) foot cubed (ft3) 0.1337 inch cubed (in.3) meter cubed (m3) 1.639x10-5 inch cubed (in.3) foot cubed (ft3) 0.0005787 liter meter cubed (m3) 0.001 liter gallon (U.S.) 0.2642 meter cubed (m3) foot cubed (ft3) 35.31 meter cubed (m3) inch cubed (in.3) 61013 meter cubed (m3) gallon (U.S.) 264.2 meter cubed (m3) liter 1000 meter cubed (m3) yard cubed (yd3) 1.308 yard cubed (yd3) meter cubed (m3) 0.7646 yard cubed (yd3) foot cubed (ft3) 27 Volumetric Flow (see Flow, Volumetric) Work (see Energy)

7 © 2012 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.

Chapter 1—Units and Properties

research has an accuracy of only two significant fig- wherey andxi are corresponding variables in I-P ures, all the coefficients should be rounded to two units, and a and bi are conversion constants. Table 1.5 places. Some constants in a function can have a much lists some conversion factors. Substituting Equations 1.6 greater impact than others, and using such a simple into Equation 1.5 results in approach can result in error valuesε , that are unaccept- ably high. ay = fb1x1  b2x2bnxn . (1.7) A more appropriate rule is to round coefficients to This equation is equivalent to Equation 1.6, but it is in I- the smallest values that will result in values ofε that are P units. Equation 1.7 demonstrates that an alternate within a predetermined limit. For many engineering form of any equation can be developed. In practice, the applications, a valueε of 1% would be reasonable, and coefficients of a function in the form of Equation 1.7 this value is used in Example 1.1. would be rearranged and rounded off. The resulting equation can be written as PHYSICAL DATA

y = f  x   x x   (1.8) The values of some physical constants are listed in 1 2 n Table 1.6. The properties of air are listed in Tables 1.7 and 1.8. The thermal properties of a number of materials wheref  is a new function with rounded off coeffi- are listed in Tables 1.9 and 1.10. cients. The level of agreement between Equations 1.7 and 1.8 can be expressed as U.S. STANDARD ATMOSPHERE af x   x x  – fx x  x  ε = ------1 2 n 1 2 n- (1.9) The barometric pressure and temperature of the air fx1x2  xn vary with altitude, local geographic conditions, and weather conditions. Altitude is the elevation above sea ε where is the error in the function,f  , due to round- level. The standard atmosphere is a standard of refer- ε ing. A positive value of means thatf  is overpredict- ence for properties at various altitudes. At sea level, the ing in comparison to the predictions of f. standard temperature is 59°F (15°C) and the standard When rounding off the coefficients, the temptation barometric pressure is 14.6959 psi (101.325 kPa). The of using a simple rule based on the accuracy of the orig- barometric pressure and temperature decrease with inal research needs to be avoided. For example, a person increasing altitude. The temperature is considered to might mistakenly think that because the original decrease linearly throughout the troposphere, which is the lowest portion of the earth’s atmosphere. The stan- Table 1.6: Some Physical Constants dard barometric pressure varies with altitude as

Acceleration of gravity 9.80665 m/s2 p = 14.6959 1– 6.87559 10–6z 5.2559 at sea level, g (1.10) p = 101.325 1– 2.25577 10–5z 5.2559 for SI. 32.174 ft/s2 Gas constant of air, R 287.0 J/kg K The standard temperature varies with altitude as 53.34 ft lbf/lbm/°R T 59–= 0.00357z (1.11) 1716. ft lbf/slug/°R T 15–= 0.0065z for SI 0.06858 Btu/lbm/°R where Standard atmospheric 101,325 Pa p = barometric pressure, psi (kPa), pressure, P atm T = temperature, °F (°C), 14.696 psi z = altitude, ft (m). 2116.2 lb/ft2 Example 1.2 shows how to calculate the standard barometric pressure. The climatic data listed in 407.19 in. H2O (60°F) Chapter 2 lists the standard barometric pressure calcu- 33.932 ft H2O (60°F) lated from Equation 1.10 for locations throughout the 1033.3 cm H2O (4°C) world. The above equations for barometric pressure and temperature are accurate from –16,400 to 36,000 ft 30.006 inch mercury (60°F) (–5000 to 11,000 m). For higher altitudes, see NASA 760.00 mm mercury (0°C) (1976).

8